It would not surprise me to see physical bookstores moving towards more of a "boutique" type strategy, where they are selling high-end luxury items, not lowest common denominator mass market goods. They would sell books to people that have already read it digitally, and want to own a physical copy. Hardcovers, typically, or leatherbound. Plus a line in first editions and other collectables.

Another alternative is the bookstore that is also a game store, a comics store, and anything else they can get their fingers into. That way when one thing is hot, they reap the benefits, but when it goes cold, they have other things to keep them afloat. For a counter-example, stores that only sell comics tend to all go out of business when the economy goes south or the comics market crashes.